1. Field of the Invention
The present invention relates in general to high-pressure pneumatic springs and, more particularly, to a new and improved valve structure for use in controlling the fluid pressure within such springs.
2. The Prior Art
It is known in the prior art to provide a valve in the end or side wall of a pneumatic spring for the purpose of enabling recharging or venting of the fluid pressure with the spring. Such known valves have typically been modified versions or designs of the low-pressure type commonly used with automobile tires or the like, These valves, however, have not been entirely satisfactory at the high pressures, e.g. up to 100 bar, used in pneumatic springs. It has been found, for example, that such tire-type valves are susceptible to leakage in high-pressure pneumatic spring use, and particularly after multiple pressure-relieving operations. This leakage is thought to result from damage to the rubber sealing element commonly used in valves of this type.